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United States Patent | 6,078,645 |
Cai ,   et al. | June 20, 2000 |
A modem monitor for monitoring full duplex communications comprises one receiver for each data stream and an echo canceler for canceling "far" echo. Prior to each receiver decoding the data stream it is designed to monitor, it replicates an echo expected to be found in its received data stream from a sample of each of the other predecoded data streams. The echo canceler then subtracts the expected echo from the received data stream to remove all far echoes caused by the other data streams. The echo canceled data stream is then decoded. The monitor can also include a data communications network interface and a sample rate converter operating with the PSTN for converting from the network transmission rate to the data transmission rate.
Inventors: | Cai; Lujing (Monmouth, NJ); Cohen; Herbert B. (Monmouth, NJ); Rogoszewicz; Richard (Camden, NJ); Wang; Mingjie (Monmouth, NJ) |
Assignee: | Lucent Technologies Inc. (Murray Hill, NJ) |
Appl. No.: | 803475 |
Filed: | February 20, 1997 |
Current U.S. Class: | 379/3; 379/406.06 |
Intern'l Class: | H04M 001/24; H04M 003/00 |
Field of Search: | 379/1,93.31,93.32,406,411,345,410 370/290,286 375/222 |
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